JPH04297627A - Controlling method for operation of hydraulic excavator - Google Patents

Abstract

PURPOSE:To improve the operability of a hydraulic excavator by a method in which a speed selective switch is provided to an operation lever in such a way as to enable the spool opening rate of control valve for stroke of operation lever and the speed of actuator to be altered according to ON-OFF operations. CONSTITUTION:A variable capacity-type hydraulic pump 9, a boom cylinder 12, and actuator such as slewing motor 13 are connected to a pipe line 11 through spool-type control valves 14 and 15. An operation lever 16 is provided, the spools of the valves 14 and 15 are moved through an electronic controller 19, and pressure oil from the pump 9 is controlled. Two large and small modes of the valve travel of the valves 14 and 15 for the same stroke of the operation lever 16 are memorized in the controller 19. A speed selective switch 22 is provided to the lever 16 and inputting the selected speed to the controller 19 is made possible. During fine-operation period, the switch 22 is turned ON to make the opening rate of spool smaller and the actuator is operated at low speeds. The excution of works can thus be attained at speeds suitable for operations and the excution accuracy can also be improued.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention can be used to
The present invention relates to a method for controlling the operation of a hydraulic excavator that allows variable rotation and speed of the working machine, and in particular enables fine operation.

0002

2. Description of the Related Art The hydraulic excavator shown in FIG.
In addition, a working machine consisting of a boom 6, an arm 7, and a bucket as a working tool, or a crusher 8 as shown in the figure, is attached to the front part of the upper revolving body 3 so as to be able to rotate freely. The operating speed of conventional excavators is as follows, as such excavators usually perform bucket work, particularly repetitive work of excavating earth and sand, scooping, turning and loading into dump trucks, etc. The speed is set at a relatively high speed to reduce cycle time and improve work efficiency.

0003

[Problem to be Solved by the Invention] However, in cases where precision is required for ground leveling work other than the above, slope finishing, etc., even in bucket work, crane work, or as shown in the figure, a crusher may be used instead of a bucket. When carrying out crushing work with a lever attached, fine control is required, but with the conventional high speed at the start of operation, even a slight movement of the lever causes a large movement, making fine control impossible.

The present invention has been made to solve the above-mentioned conventional problems, and it not only ensures operation speed during normal excavation and loading work, but also reduces the initial stroke of lever operation in work that requires fine operation. The purpose of this project is to provide a method for controlling the operation of a hydraulic excavator that has a low speed and is variable depending on the purpose of the work.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides actuators and control valves for operating running, turning, working equipment, etc. in the discharge pipe of a hydraulic pump, and also provides actuators and control valves for operating operating equipment such as traveling, turning, and working equipment. In a hydraulic excavator configured to control direction switching, a speed selection switch is attached to the operation lever, and when the switch is turned ON or OFF, the control valve is controlled via an electronic controller to control the operation stroke of the lever. The supply flow rate was controlled by changing the spool opening ratio, and the actuator was thereby made variable speed with two modes to achieve the objective.

[0006]

[Operation] Therefore, in normal bucket work such as excavation and swing loading work, if the speed selection switch is in the OFF state, each actuator will start at a relatively fast speed stored in the controller in advance as the standard mode, increasing work efficiency. I'll give you. In this way, the standard mode is set with the switch normally turned off, and bucket operations such as digging, turning, and loading are performed.

[0007] In addition, when fine operation is required in the above-mentioned bucket work, land leveling, slope finishing, or special work, by turning on the speed selection switch and entering fine operation mode, the controller can be set in advance. The opening ratio of the control valve spool with respect to the stroke of the operating lever becomes small, and the turning speed at the initial stage of the lever stroke becomes slow, allowing fine operation.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a control circuit for a boom cylinder and a swing motor of a working machine as an example of the various actuators in the hydraulic excavator already described as the first embodiment of the present invention to simplify the explanation. In the figure, 9 is the engine 10
A boom cylinder 12 and a swing motor 13 are connected to a discharge pipe 11 of the pump 9, and actuators 12 and 13 are connected to the pipe 11. Spool-type control valves 14 and 15 are interposed to control direction and speed.

Each of the control valves 14 and 15 is controlled by a potentiometer 17 attached to the base of the operating lever 16 to set the operating stroke of the lever 16 to the neutral position (N).
Detection of the operating angles (Q1) and (Q2) in the longitudinal and lateral directions, as well as in each of these directions, is input to the electronic controller 19 via the electric circuit 18, and the controller 19
The spools of the control valves 14 and 15 are moved in the front-rear direction via electric circuits 20 and 21 to control the pressure oil from the hydraulic pump 9, and then the boom cylinder 12 and swing motor 13 are controlled.
is supplied to

In such a control circuit, the operating lever 16
A speed selection switch 22 is attached to the top of the clip, and the ON/OFF operation of the switch 22 is inputted to an electronic controller 19 via an electric circuit 23. Two modes are stored in advance as these actuator speeds by varying the opening ratio of the control valves 14 and 15 with respect to the stroke of the operating lever 16, and the first mode is a reference mode and is intended for relatively fast bucket work. The aperture ratio is set to be large in order to speed up the telescopic movement of the boom cylinder 12 and the rotation of the swing motor 13 from the beginning of the lever stroke. Next, the second mode is a fine operation mode in which the aperture ratio is set small in order to slow down the actuator speed.

FIG. 2 shows the opening ratio of the control valves 14 and 15 with respect to the stroke of the operating lever 16 in the first mode (reference mode) and second mode (fine operation mode), and it is clear from the illustration that As shown, the actuator speed in the second mode is slower than that in the first mode for the same stroke.

When the speed selection switch 22 is in the OFF state, the first mode is always used as the reference work and is operated at a relatively fast speed, and then the switch 22 is turned ON.
When activated, the controller 19 receives this ON signal, switches from the first mode to the second mode, and operates each control valve 14,1.
A fine operation command is issued to 5 to operate at low speed.

FIG. 3 shows a control circuit as a second embodiment of the present invention, which is particularly intended for turning operation control, and similarly to the first embodiment described above, the control circuit has two modes: the first mode (reference turning mode) and the second mode. In the figure, 24 is a swing motor consisting of a variable displacement hydraulic motor, and the swing motor 24 controls the pressure oil discharged from the hydraulic pump 9. The swing pinion 27 is supplied through the control valve 25 and driven to rotate left and right, and is attached to the motor shaft 26 to rotate the swing ring 28.

A tilt angle control cylinder 31 is attached to the swing motor 24 via a pipe 30 from a pilot pump 29, and is moved by a pilot oil pressure to extend and retract. An on-off valve 32 for changing and controlling the tilting angle is provided in the pilot pipe line 30.

Similarly to the first embodiment described above, the speed selection switch 34 attached to the operating lever 33 is turned on and off.
The FF operation is input to the controller 36 via the electric circuit 35, and the operating direction and operation stroke of the operating lever 33 are detected by the potentiometer 37 and input to the controller 36 via the electric circuit 38. It looks like this. The controller 36 that receives these input signals stores and calculates them, and then outputs them through the output circuit 39.
40, a control valve 25 and a motor tilting angle control cylinder 3
1, an activation signal is commanded.

In controlling the operation of the swing motor 24, the speed selection switch 34 is turned on and off.
The rotation speed can be varied by mode. In the first mode (standard swing mode), the machine stands up and turns at a relatively fast speed as normal bucket work, and in the second mode (fine operation mode) The lever is designed to rise at a gentle turning speed at the beginning of the lever stroke to suit the required work. These first and second swing modes are stored in the controller 36, and when output, the tilt angle of the swing motor 24 is controlled to vary the swing speed.

FIG. 4 shows the relationship between the tilt angle of the swing motor and the switching time when the speed selection switch 34 is turned on to switch to the second mode (fine operation mode). switch O
Figure 5 shows that the tilt angle is set to gradually increase as the lever stroke increases with N.
4 shows that the rotation speed of the swing motor is set to gradually decrease with respect to the switching time accompanying the change in the tilt angle in FIG.

[0018]

[Effects of the Invention] Since the present invention is constructed as described above, the work efficiency can be greatly improved because the operation can be easily performed at the operating speed suitable for each work by turning the speed selection switch ON or OFF according to the purpose of the work. . Therefore, operator fatigue is alleviated, and even non-skilled workers can perform tasks that require high precision.

[Brief explanation of drawings]

FIG. 1 is a control circuit diagram showing a first embodiment according to the present invention.

FIG. 2 is a diagram showing the relationship between the lever stroke and the opening ratio of the control valve in the two modes.

FIG. 3 is a control circuit diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the switching time and the tilt angle of the swing motor in the second mode.

FIG. 5 is a diagram showing the relationship between switching time and rotation of the swing motor in the second mode.

FIG. 6 is a schematic side view of a hydraulic excavator.

[Explanation of symbols]

9...Hydraulic pump 12...Boom cylinder 13...Swivel motor 14...Boom cylinder control valve 15... Control valve for swing motor 16...operation lever 17... Potentiometer 19...Electronic controller 22...Speed selection switch 24...Swivel motor 25... Control valve for swing motor 29...Pilot pump 31...Tilt angle control cylinder 32...Opening/closing valve 33...operation lever 34...Speed selection switch 36...Electronic controller 37...Potentiometer

Claims (2)

[Claims] [Claim 1] A hydraulic excavator in which the discharge pipe of the hydraulic pump is provided with actuators and control valves for running, swinging, working equipment, etc., and direction switching is controlled by lever operation. A speed selection switch is attached to the operating lever, and the speed selection switch is turned on and off.
Hydraulic excavation characterized in that the supply flow rate is controlled by changing the opening ratio of the control valve with respect to the operation stroke of the lever via an electronic controller by F operation, thereby making the actuator variable speed consisting of two modes. How to control the machine. 2. The swing operation actuator is a variable displacement hydraulic motor equipped with a tilting angle control cylinder, and a control valve for the tilting angle control cylinder is provided in a pilot pump conduit, and the control lever is provided with a control valve for the tilting angle control cylinder. By turning on and off the attached speed selection switch, the tilt angle control cylinder is actuated via the electronic controller to change the aperture ratio of the swing motor and control the supply flow rate, thereby controlling the swing motor in two modes. 2. The method of controlling the operation of a hydraulic excavator according to claim 1, wherein the rotation speed is variable.